T.K.
You need this book:
The Milk Memos: How Real Moms Learned to Mix Business with Babies-and How You Can, Too
http://www.amazon.com/Milk-Memos-Learned-Business-Babies/...
Pumping at work just takes chutzpah. I found that I made a lot of friends in the ladies room. Women would ask me about it, tell me they did it a few years ago, their sister was doing it, or "what is that thing?! Dialysis?!"
In my own experience, I think my kid got a little bit less breast milk and a little bit more formula when I went back to work, but I was okay with that, in the grand scheme of every thing the great thing about breast milk is that it doesn't have to be exclusive; even if you do a little, the benefits are there.